Child ; China ; epidemiology ; Health Policy ; Humans ; Infant, Newborn ; Iodine ; deficiency ; therapeutic use ; Population Surveillance ; methods ; Program Evaluation ; Sodium Chloride, Dietary ; therapeutic use

Objective The present study has been designed to investigate the impact of dietary iodine/sodium intake on blood lipid metabolism in mice. Methods According to body weight and gender, two hundred and sixty Balb/c mice were randomly divided into 2 groups including normal sodium group(Na) and low sodium group(LNa), with 130 animals per group. Each group were then randomly further divided into 5 sub-groups according to the amount of iodine intake: ① severe iodine deficiency(SID); ② mild iodine deficiency(MID); (③normal iodine (NI); ④ 10-fold high iodine ( 10HI ); (⑤ 50-fold high iodine (50HI), 10 groups in total, 26 per group.Eight months later, the body weight and the levels of urinary iodine, thyroid hormones and total cholesterol (TC),Results In Na group, the levels of TG and TC in male mice of SID group[ (1.64 ± 0.35), (3.88 ± 0.35 )mmol/L]and MID group[ ( 1.67 ± 0.31 ), (3.41 ± 0.66)mmol/L] were significantly higher than that of NI group[ ( 1.49 ± 0.42), (3.25 ± 0.47)mmol/L] and the levels of TG in female mice of SID group[(1.52 ± 0.22)mmol/L] were significantly higher than that of NI group[ (1.23 ± 0.22)mmol/L]. In addition, the levels of TG in male mice of 10HI and 50HI groups [ ( 1.16 ± 0.23 ), ( 1.21 ± 0.27 ) mmol/L ] were significantly lower than that of NI group [ ( 1.49 ± 0.42)mmol/L, all P ＜ 0.05], the levels of TC in female mice of 10HI and 50HI groups[(2.37 ± 0.49), (2.48 ± 0.37)mmol/L] were significantly lower than that of NI group[ (2.84 ± 0.37) mmol/L, all P ＜ 0.05 ]. In LNa group,the levels of TG and TC in male mice of SID group[ (1.39 ± 0.40), (3.33 ± 0.46 )mmol/L] were significantly lower than that of NI group [(1.30 ± 0.28), (3.00 ± 0.53) mmol/L, all P ＜ 0.05], the levels of TG, TC and LDL in female mice of SID group[ (1.48 ± 0.26), (2.76 ± 0.43), (0.62 ± 0.22)mmol/L], the levels of LDL in female mice of MID group[ (0.60 ± 0.17 )mmol/L] were significantly lower than that of NI group[(l.22 ± 0.36), (2.51 ± 0.38),(0.48 ± 0.08), (0.48 ± 0.08)mmol/L, all P ＜ 0.05], the levels of TG in male mice of 10HI and 50HI group [ (1.12 ± 0.22), (0.90 ± 0.11 )mmol/L] were significantly lower than that of NI group (all P ＜ 0.05 ), the levels of TC in female mice of 10HI and 50HI groups[ (2.35 ± 0.34), (2.37 ± 0.37)mmol/L], the levels of LDL in female mice of 50HI group[(0.65 ± 0.18)mmol/L], were significantly lower than that of NI group(all P ＜ 0.05). In Na group, the levels of thyroid hormones were distinctively decreased in SID group[TT4(0.00 ± 0.00)nmol/L, FT4 (0.93 ± 0.42)pmol/L, TT3(0.49 ± 0.07)nmol/L, FT3(2.86 ± 0.37)pmol/L] and MID group [TT4 (17.15 ± 15.26)nmol/L, FT4( 18.46 ± 4.31 )pmol/L, TT3(0.67 ± 0. 10)nmol/L, FT3(3.18 ± 0.24)pmol/L] compared with that of the NI group [TT4 (37.15 ± 15.26)nmol/L, FT4(28.46 ± 4.31)pmol/L, TT3(0.85 ± 0.10)pmol/L, FT3(3.87 ± 0.24)pmol/L, all P ＜ 0.05 ]. In LNa group, the levels of thyroid hormones were distinctively decreased in SID group [TT4 (0.00 ± 0.00) nmol/L,FT4(1.03 ± 0.78)pmol/L, TT3(0.51 ± 0.05)nmol/L, FT3(3.01 ± 0.17)pmol/L] and MID group[TT4(19.76 ± 12.22)nmol/L, FT4(21.46 ± 5.37)pmol/L, TT3(0.71 ± 0.21)nmol/L, FT3(3.56 ± 0.23)pmol/L] compared with that of the NI group[TT4(36.23 ± 14.72)nmol/L, FT4(30.96 ± 6.33)pmol/L, TT3(0.89 ± 0.20)nmol/L, FT3(4.05 ± 0.24)pmol/L, all P ＜ 0.05]. Conclusions Dietary iodine intake plays an important role in the blood lipid metabolism. Iodine deficiency could increase while iodine excess could decrease the levels of serum TG, TC or LDL in mice. Monitoring the amount of iodine intake during sodium restriction should have an important role in effective prevention and treatment of cardiovascular disease.

Objective To investigate the effects of iodine excess on mitochondrial superoxide production and mitoehondrial membrane potential(△ψ)changes in Fisher rat thyroid cell line(FRTL)cells.Methods FRTL cells were treated with 10-4mol/L potassium iodine(KI),10 U/L thyrotropin(TSH),10-4 mol/L KI+10 U/L TSH respectively for 24 h.Effects on cell proliferation were assayed by methyl thiazolyl tetrazolium(MTT)colorimetric method.Changes of mitochondrial superoxide production and △ψ were measured by live cell imaging and spectrofluorometer using MitoSOX and rhodamine 123(rh123)respectively.Results Absorbance(A)in the KI group (0.794±0.144)showed a significant decline compared to the control group(1.000 ±0.183,P<0.05),whereas a significant elevation was observed in the TSH group(1.215±0.156,P<0.05).No significant differences was found between the KI+TSH group(1.025±0.254)and the control group(P>0.05),but the former was marked higher than the KI group(P<0.05).Compared to the control group(9.74±3.24).MitoSOX mean fluorescence intensity (MFI)in the KI and KI+TSH groups(18.16±6.57,13.33±2.92)were significantly increased(all P<0.05),which was a significant decline in the TSH group(6.64±2.15,P<0.05).MitoSOX MFI in the KI+TSH group was lower than the KI group(P<0.05).Rh123 MFI in the KI and KI+TSH groups(210 593±31 328,295 525±34 243)showed significant decline than the control group(407 824±37 198,all P<0.05).Compared with the KI group.the KI+TSH group pronouncedly attenuated the reduction of Rh 123 MFI(P<0.05).No significant differences of Rh 123 MFI were found between the TSH group(411 187 ± 72 852) and the control group(P > 0.05). Conclusion Iodine excess (10-4 mol/L KI) may lead to peroxide damage on the mitochondria of FRTL cells, and cell proliferation is inhibited. Combining treatment with 10 U/L TSH may attenuate mitochondrial peroxide damage and inhibition of cell proliferation caused by iodine excess.

Objective To study the expression level of thyroid insulin-like growth factor-Ⅰ (IGF-Ⅰ) in iodine deficiency and excess mice and the effect of thyroid gland IGF-Ⅰ in the thyroid morphological change. Methods Forty-eight Balb/c mice were chosen as studied objects,weighing about 16 g. They were divided into three groups: low iodine(LI,iodine content of 50 μg/kg in feed,drinking deironized water) group,normoi(NI,iodine content of 300 μg/kg in feed,drinking deironized water) group and high(HI,iodine content of 300 μg/kg in feed,iodoine of content 14 700 μg/kg in drinking) group,16 mice in each group. Mice were put to death after 12 weeks and taken out of their thyroid gland. The body weight,absolute and relative weights of thyroid gland were measured and the morphological change of thyroid gland were observed under microscope. The expression levels of thyroid gland IGF-Ⅰ mRNA and protein were detected by RT-PCR and immunohistochemistry,respectively. Results There were statistical significances between groups of thyroid absolute and relative weights(F = 315.881,405.921,all P < 0.01). LI group [(10.71±4.03) mg,(44.98±15.39)mg/100 g body weight]and HI group [(3.42±1.17)mg,(13.50± 3.89)mg/100 g body weight]had heavier thyroid absolute and relative weights than NI group[(2.11±0.53)mg,(8.35±1.98)mg/100 g body weight,all P < 0.01]. Under microscopy,the thyroid follicle capacity grew down and the follicle quantity grew up in LI group,the epithelium was stylolitic,the colloid diminished or absence in follicular cavity,while HI group presented colloid accumulation without follicular hyperplasia. The expression level of thyroid gland IGF-Ⅰ mRNA in LI group(1.03±0.32) was more than that in NI(0.65±0.19) and HI(0.59± 0.20) groups(F= 7.518,P< 0.01). In contrast to NI,there was no difference in the expression level of thyroid gland IGF-Ⅰ mRNA in HI group(P > 0.05). The brownish particles of LI group were more than NI and HI groups in the thyroid follicle epithelium by immunohistochemistry,while HI group was less than NI group. Conclusions The mice of iodine deficiency presented follicular hyperplasia goiter,the mice of iodine excess presented colloid accumulative goiter. The change of IGF-Ⅰ mRNA and protein expression may participate morphologleal change,indicating autocrine IGF-Ⅰ of thyroid gland may play an important role in regulating goiter formation.

Objective To study the effects of iodine deficiency during pregnancy on fetal iodine metabolism and thyroid function. Methods Wistar dams were randomly divided into four groups: severe iodine deficiency(SID), moderate iodine deficiency(MoID), mild iodine deficiency(MiID) and normal iodine(NI). All the dams were fed with iodine deficient food(iodine contents: 50 μg/kg) and drinking water with different doses of KI (0,54.9,163.8,381.7 μg/L) for 3 months till mating. Iodine was supplied at the dose of 1.24 μg/d(SID), 2.50 μg/d(MoID), 5.00 μg/d(MiID) and 10.00 μg/d(NI), respectively. The dams and their fetuses on gestation of 20 days were studied. Urine iodine of dams and iodine contents in fetal amniotic fluid were measured by As3+-Ce4+catalytic spectrophotometry using ammonium persulfate digestion. And blood iodine in pregnant rats and iodine contents in placental tissue were measured by As3+-Ce4+catalytic spectrophotometry in dry ash of samples in KClO3-ZnSO4-K2CO3-NaCl. Thyroid hormone levels in mother serum and in fetal amniotic fluid were detected by chemiluminascent assay, and their thyroid glands were weighted and carefully observed. Results ①Iodine content in urine and blood of pregnant rats and amniotic fluid of fetal rats reduced along with their decrease of iodine supply. Urine iodine median of rats in 4 groups(NI: 353.7 μg/L; MiID: 115.9 μg/L; MoID: 26.9 μg/L; SID: 0 μg/L) were statistically significant(χ2=32.884, P < 0.01). Blood iodine level in MoID and SID[(29.4±18.6), (11.7± 7.0)μg/L]was significantly lower than that in NI[(49.1±23.0)μg/L, P < 0.05 or < 0.01]. In iodine deficiency groups, there was a decreasing trend in iodine contents of fetal amniotic fluid[MiID: (48.3±23.1)μg/L; MoID: (29.2±14.7)μ/L; SID:(19.5±6.7)μg/L]and an increasing tendency in iodine contents of placental tissue [MiID: (0.57±0.26)μg/g, MoID: (0.53±0.34)μg/g; SID: (0.53±0.15)μg/g], but there was no statistical significance(P>0.05). ②In SID, TT4[(14.3±4.1)nmol/L]and FT4[(10.8±3.6)pmol/L]were lower than that in NI[(28.4±19.3)nmol/L, (20.2±8.0)pmol/L, P < 0.05 or < 0.01], while that in MoID[(22.1±6.1)nmol/L, (18.5±4.1)pmol/L]and MiID[(25.5±13.1)nmol/L, (18.6±8.4)pmol/L]were decreased without statistical significance(P > 0.05). And FT3/FT4 ratio(0.34±0.16), absolute[(48.4±22.7)mg]and relative weights[(144± 76)mg/kg]of thyroid gland in pregnant rats were respectively higher than that in NI[0.16±0.02, (19.5±3.1)mg, (66±10)mg/kg, P<0.01]. But that in MoID[0.19±0.04, (27.0±5.7)mg, (84±19)mg/kg]and MiID[0.17± 0.06, (25.0±8.9)mg, (78±25)mg/kg]were increased without statistical significance(P > 0.05). A visibly congestive enlargement thyroid was found in SID, while thyroid mildly enlarged in MoID and MiID. ③Compared with NI [(2.38±1.55)pmol/L,0.50±0.18], the FT4 levels [(1.07±0.87) pmol/L]in amniotic fluid were significantly decreased (P < 0.05) and the FT3/FT4 ratio (1.96±0.61) was significantly increased (P < 0.01) in SID. There were no statistical significances(P > 0.05) in other 3 groups[MiID: (2.77±0.90)pmol/L,0.46±0.15; MoID: (2.35±0.76)pmoL/L,0.61±0.21]. A visible thyroid enlargement with hyperemia was observed in SID fetus while in other 2 experiment groups their thyroids were only mildly congested. Conclusions Severe iodine deficiency during pregnancy can result in both mother and fetus overt hypothyroidism. The fetal thyroid hormone levels in mild iodine deficiency status is close to normal levels because of maternal and placental compensation. Moreover, both the dam and the fetus suffer from the negative effects in moderate iodine deficiency during pregnancy.

Objective To observe the effects of iodine deficiency and iodine excess on the lipid metabolism in an experimental hypothyroid model of mice and to explore the roles of iodine independent of its role in thyroid hormones. Methods Female Balb/c mice were randomly divided into 6 groups: control, severe iodine deficiency (SID), mild iodine deficiency(MID), normal iodine (NI), 10-fold high iodine (10HI) and 50-fold high iodine(50HI), 10 in each group. The mice in control group were fed with low iodine forage, other mice were fed with low iodine forage containing 0.2% methylthiouracilum. All mice drank deionic water containing different concentrations of potassium iodide(KI). The iodine content in water was 326.79, 0, 196.08,326.79, 385621, 19 542.50 μg/L, respectively. After three months, thyroid hormones in the serum were determined by radioimmunoassay.Also, the blood samples were analyzed for total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesteiol (HDL-C) and low density lipoprotein cholesterol (LDL-C) and measured enzymatically by automatic analyzer. Results①The levels of Tr4 in SID[(21.27 ± 9.63)μg/L], MID[(23.41 ± 3.93)μg/L], NI[(22.57 ±4.66)μg/L], 10HI [(21.07 ± 5.03) μg/L] and 50HI groups [(21.46 ± 5.90) μg/L] were distinctively decreased compared with control group[(42.15 ± 8.26)μg/L, all P ＜ 0.01]. There were no statistical significant differences of TT3 between different groups (F = 0.99, P > 0.05 ). ②The level of TG in 10HI group [ ( 1.17 ± 0.16)mmol/L ] was obviously decreased compared with control [(1.39 ± 0.22 )mmol/L] and NI groups[(151 ± 0.22)mmol/L, all P＜ 0.05].Both TG and TC in 50HI group[(1.18 ± 0.22), (1.78 ± 0.15)mmol/L] were significantly decreased compared with control [( 1.39 ± 0.22), (2.14 ± 0.37)mmol/L] and NI groups [(1.51 ± 0.22), (2.00 ± 0.15)mmol/L, all P ＜ 0.05].The difference of serum HDL-C and LDL-C between the groups was not significant(F = 0.55,0.54, all P ＞ 0.05 ).Conclusions Dietary iodine plays a role in the metabolism of serum lipids independent of thyroid hormones.Thus, monitoring the amount of iodine intake during sodium restriction should also be taken extremely important for effectively prevention and cure of cardiovascular disease.

ObjectiveTo study the role of alpha smooth muscle actin (α-SMA) positive cells (pericytes)in early myocardial ischemia.MethodsThirty healthy female Wistar rats were randomly divided by body weight into normal control group and subcutaneous multi-point injection of isoprenaline(Isp) group.Five rats were anesthetized after 0,2,4,6,12,24 and 48 h in each group.Blood was taken in eyeballs and,serum was separated,heart was taken and fixed in 4％ paraformaldehyde solution.The myocardial enzymes [serum apartate aminotransferase ( AST ),lactate dehydrogenase (LDH),creatine kinase (CK),creatine kinase isoenzymes (CK-MB)] were determined by biochemical automatic analyzer,the expression of α-SMA and vimentin in myocardial tissue was detected by immunohistochemical staining and changes of pericytes in early myocardial ischemia was observed by morphometric analysis.ResultsThe level of myocardial enzymes AST[(160.25 ± 3.86),(172.60 ± 8.82),(192.20 ± 25.35)U/L],and LDH[(1466.25 ± 643.38),(1645.20 ± 326.83),(1701.60 ± 640.06)U/L],12,24 and 48 h after subcutaneous injection of Isp,were higher than that[(129.18 ± 19.65),(849.45 ± 248.54)U/L,all P ＜ 0.05] of the control group.The level of CK[(1097.60 ± 301.57),(1247.20 ± 243.84),(1263.75 ± 271.22),(1448.00 ± 647.00),(1268.40 ± 479.81)U/L],and CK-MB[(217.12 ± 35.89),(229.08 ± 97.11),(251.70 ± 46.82),(318.80 ±77.76),(249.04 ±:98.54)U/L],4,6,12,24 and 48 h after subcutaneous injection of Isp,were higher than that [(713.45 ± 146.30),(147.05 ± 25.75)U/L,all P ＜ 0.05] of the control group.The number of α-SMA positive cells(61.00 ± 17.25),4 h after Isp injection,was significantly increased compared with that(28.20 ± 5.81,18.20 ± 2.17) of 24 and 48 h after Isp injection.The number of α-SMA positive cells in 48 h group was less than that(50.00 ± 3.61,P ＜ 0.05) of 6 h group.The number of vimentin positive cells in 6,12,24,48 h groups (4.17 ± 2.49,5.24 ± 2.84,8.37 ± 2.18,7.73 ± 2.49) were higher than that(1.88 ± 1.85,2.21 ± 1.54) of the control group and 4 h group(all P ＜ 0.05).Compared with 24 and 48 h groups,the level of vimentin protein was increased in 6 and 12 h groups(P ＜ 0.05).ConclusionThe number of pericytes in early myocardial ischemia is higher than that of other mesenthymal cells,and pericytes may be the main effector cells in the generation and development of myocardial fibrosis.

In hyperthyroid,hypothyroid and subclinical hypothyroid patients,the positive rate and level of the thyroid autoantibodies were all remarkably higher than those in the control group.The positive rate of thyroid peroxidase antibody (TPOAb) was higher than those of thyroglobulin antibody and thyroid microsome antibody in each group.In the group with restored thyroid function,the average level of TPOAb was significantly decreased, suggesting that TPOAb could be taken as an important indicator in evaluating the treatment and prognosis of autoimmune thyroid diseases.

Objective To observe the levels of serum leptin in Gaves disease(GD)and thyroiditis(HT)Datients and to discuss the immunological role of leptin in the pathogenesis of autoimmune thyroid disease(AITD).Methods 102 newly diagnosed female AITD patients were divided into 3 groups:GD hyperthyroid group,HT hypothyroid group and subclinical hypothyroid group.Age,sex and BMI-matched 27 euthyroid,healthy subjects served as controis.The levels of FT3,FT4 and sTSH were determined by immunofluorometrie assay.ELISA kit was aDplied to measure the levels of serum leptin.Results Serum FT3 and FT4[(19.74±15.39),(78.25±58.68)pmol/L]levels of GD hyperthyroid patients were obviously higher than those of the controls[(4.87±0.25),(15.96±3.15)pmol/L,P＜0.01],but serum sTSH and leptin levels[(0.15±0.08)mU/L,(8.73±1.92)μg/L]were obviously lower than those of the controls[(3.81±0.19)mU/L,(12.38±3.51)μg/L,P＜0.01or＜0.05].Serum FT3 and FT4[(3.36±0.26),(6.95±3.29)pmol/L]levels of HT hypothyroid patients were obviously lower than those of the controls(P＜0.05),but serum sTSH and leptin levels[(45.48±35.83)mU/L,(17.17±3.82)μg/L]were obviously higher than those of the controls(P＜0.01 or＜0.05).Serum FT3 and FT4[(4.67±0.60),(14.87±2.14)pmol/L]levels of subclinical hypothyroid patients had not statistical difference comparing with those of the controls(P＞0.05),but serum sTSH and leptin levels[(13.67±8.66)mU/L,(16.25±3.67)μg/L]were obviously higher than those of the controls(P＜0.01 or＜0.05).Conclusions Leptin might have an immuoregulation role in the pathogenesis of AITD.In addition,serum levels of leptin in AITD is also influenced by many other related hormones.

Objective To evaluate the effect of health education in controlling the iodine deficiency diserders(IDD) in order to provide reference data for the further prevention and control. Methods Each village of 3 towns in Congjiang County was selected in 2007, where the health education lasting for 10 months had been implemented in the school students of 3-6 grade and the villagers. The school students of 3-6 grade and 30 housewives in the villagers were investigated for their IDD control knowledge, the salt consuming conditions as well as the sales of both rough and fine salt at a salt retail site in each village before and after the health education was implemented. Results The awareness rate of the knowledge of IDD control in the students and housewives was 91.4% (581/636) and 78.3% (282/360), respectively after intervention, which significantly increased (χ2= 532.044, 326.117, both P < 0.01) compared with the rate of 28.2% (184/652) and 11.4% (41/360) before intervention. The proportion of consuming fine salt was 91.8%(146/159) and 95.6%(86/90), significantly inereased(χ2= 236.623, 135.350, both P < 0.01) compared with 6.1%(10/163) and 7.8% (7/90) found before intervention. The selling proportion of fine salt at the salt retail site in the village was 60.0%(900/1500), significantly increased(χ2= 824.176, P < 0.01) compared with 10.0%(150/1500) before intervention. Conclusions Health education and promotion is solid foundation for effectively controlling IDD, through which the students and villagers are actively and voluntarily involved in the program and hence have formed good living and hygiene habits, thus expected effect has been obtained.